Control mechanism



NM. 23, 1943. A L 2,334,857

CONTROL MECHANISM Filed Dec. 5, 1940 2 Sheets-Sheet 1 INVENTOR YTkazryas )ZLBQZZ BY v g. fiuf ATT'o fifss.

T. M. BALL CONTROL MECHANISM Nov. 23, 1943. 2,334,857

Filed Dec. 5,1940 2 Sheets-Sheet 2 INVENTOR ATTORNEY Patented Nov. 23,1943 CONTROL MECHANISM Thomas M. Ball, Detroit, Mich., assignor toChrysler Corporation, Highland Park, Mich, a corporation of DelawareApplication December 5, 1940, Serial No. 368,575-

13 Claims.

This invention relates to throttle control devices especially inconjunction with motor vehicles. 1

It is well known at this time that an internal combustion engine has atendency to stall when, at relatively low vehicle driving speeds, thedriver suddenly releases the usual accelerator pedal to allow thethrottle valve to suddenly close. This characteristic is known to beespecially pronounced in motor vehicles equipped with a fluid couplingthrough which the drive is taken.

Heretofore it has been customary to provide a dashpot for retarding thelast part of throttle closing so that when the accelerator pedal issuddenly released, the throttle has its final closing movement retardedso that the fuel supply system and other factors which are disturbed andwhich give rise to engine stalling have an opportunity to becomebalanced or adjusted to the coast conditions whereupon the throttlevalve is allowed to fully close.

The foregoing throttle retarding devices have the disadvantage that theyoperate at relatively high vehicle speeds thereby preventing full use ofthe engine as a brake because when the accelerator pedal is released,the throttle valve does not fully close until after an appreciable timeduring which the dashpot acts. Furthermore, where the vehicle isequipped with a change speed mechanism functioning as a characteristicof allowing the engine to coast down in its speed, the foregoing dashpotdevices have the disadvantage of increasing the time required to effectchange in the speed ratio as the dashpot delays the engine retardation.I

In my copending application Serial No. 360,476, filed October 9, 1940,now Patent No. 2,314,570 issued March 23, 1943, I have provided acontrol for the dashpot so arranged as to overcome the foregoingdifficulties by incorporating means for rendering the dashpotineffective for throttle closing retardation at times when the enginedoes not tend to stall as an incident to udden release of theaccelerator pedal. 7

My present application is directed to improved means for controlling theretarding device and may, if desired, be employed in the transmissionsystem disclosed in my aforesaid application.

One object of my invention is to provide a simplified control forthrottle closing dashpot devices.

Another object is to provide a dashpot control comprising anelectromagnetic device especially arranged for mounting in associationwith the dashpot-fluid container but free from danger of leakage of thefluid in proximity to the electromagnet.

Another object is to provide an improved electromagnet for use with athrottle closing dashpot or for general applications to a variety ofdevices wherein the magnet is separated from the armature by wall whichallows the magnetic flux to pass therethrough.

An additional object is to provide an improved electromagnet of theaforesaid character wherein the electromagnet and armature are separatedby a relatively thin wall of non-ferrous material which allows thedesired magnetic action to take place while effectively sealing theregions on each side of the wall from each other.

A still further object is to provide an improved dashpot controlespecially adapted for use with throttle systems.

Further objects and advantages of my invention will be more apparentfrom the following illustrative embodiment thereof, reference being hadto the accompanying drawings in which:

Fig. 1 is a side elevational view somewhat diagrammatically illustratingmy throttle control applied to a vehicle driver system, parts beingbroken awa to show the governor.

Fig. 2 is an elevational view taken as indicated by line 2-2 in Fig. l,the dashpot mechanism being shown in cross-section.

Fig. 3 is a wiring diagram illustrating the electrical control for thedashpot.

Fig. 4 is a fragmentary side elevational view taken as indicated by line4-4 in Fig. 2.

Fig. 5 is a View generally similar to Fig. 2 but illustrating a modifiedform of my invention.

Fig. 6 is a wiring diagram for the Fig. 5 modified arrangement.

My invention may be used advantageously in connection with any vehiclepower transmission system. In my aforesaid copending application I haveillustrated one drive system which is equally well adapted for use withmy'present improvements. However, in order to illustrate the principlesof my present invention I have shown the same in connection with asimplified background of vehicle drive, it being understood that thisdrive mechanism may take a variety of forms especially in drive systemswhere, at times, it is desired to allow the engine to rapidly slow downupon release of the accelerator pedal without retarding throttle closingby a dashpot control which, at other times, is desired to preventtendency of the engine to stall.

The customary internal combustion engine A is arranged as is now wellknown to drive through suitable clutch mechanism in housing B, thencethrough any desired type of transmission change speed mechanism C to theoutput shaft 26 for driving the usual vehicle rear drive wheelsaccording to standard practice. The clutch mechanism at B may comprise afluid coupling or friction type clutch or both.

The engine intake manifold 2| is fitted with an air cleaner 22 andcarburetor D, the usual throttle valve 23 being operated by lever 24 andlink 25 connected by linkage 26 to accelerator pedal 27 yieldingly urgedby compression spring 28 to a position of closing the throttle 23. InFig. l the accelerator pedal is shown in a position of part openthrottle.

On the side of the intake system opposite to that seen in Fig. 1, thethrottle shaft 29 (Fig. 4) is fitted with a lever 30 having a terminalshoulder 3| which, prior to closing movement of throttle 23 engages theshoulder 32 of a lever 33 which slides vertically in guide 34. Thislever has its upper end offset at 35 extending into the dome 36 of coverE for the float bowl 3'! of carburetor C.

The oifset 35 is connected to the upper end of a piston rod 38 whichextends down for connection with a piston 39, a spring 40 yieldinglyurging the piston and lever 33 upwardly to the positions illustrated. Anadjustable stop 4| limits the upward piston movement and variablydetermines the extend of the dashpot action on throttle closing.

Piston 39 operates in an open top cylinder 4| which therefore is filledwith gasoline from the bowl 3?. When the piston moves downward, assumingthe chamber 42 below the piston to be closed against fluid escape, thefluid must escape through the metering restricted opening 43 therebyretarding the downward movement. The return or upward stroke of thepiston, by spring 46, is unrestricted by reason of a check valve 44which at such time is free to open for passage of the fluid from thestorage chamber at 45 to chamber 42. Therefore when the acceleratorpedal is released, under certain conditions presently apparent, thelever 30 engages lever 33 just before throttle 23 closes and the lastpart of the throttle closing movement is retarded by the aforesaiddashpot generally designated at F, the spring 28 gradually overcomingthe dashpot action to fully close the throttle and compressing spring 40which, of course, is of less force than spring 28.

The carburetor bowl 3'! is formed with a cylinder or guideway 46 whichslidably receives a plunger 47 having a stem 48 engageable with adashpot-control ball or valve 49 which, in Fig. 2, seats on a pin 56disposed across passage 51 which is open to chamber 42. When the dashpotis operating, the fluid displaced by piston 39 enters passage 5| andcauses ball 49 to seat at 52 thereby preventing escape of the fluid fromthis passage and requiring the fluid to flow through restriction 43. Atother times a spring 53 acts on plunger 41 to hold ball 49 unseated asin Fig. 2 and at such times the dashpot F is inoperative as a retardingdevice because piston 39 is then free to move downwardly as the liquidfreely flows through passage 5|, around ball 49 and in the space betweenstem 48 and by-pass cylinder 54 and thence to cylinder 46 and out atvent 55 to the reservoir 45.

The bowl cover E, and the carburetor housing 31 if desired, ispreferably of a non-ferrous metal such as zinc alloy now widely employedfor casting such parts. The cover E is secured by fasteners 56 to thetop of bowl 31, a sealing gasket 5'! preventing gasoline leakage out ofthe bowl.

Mounted on the top of cover E is an electromagnet' G comprising aferrous cover 58 secured to cover E by fasteners 59, and a ferrous core60 around which is wound the conductor coil (SI of the electromagnet.Cover E is formed with a cavity 62 in its under face thereby forming acover wall 63 of relatively thin cross-section below the electromagnet.Plunger 47 has its upper end outwardly flanged at 64 for movement incavity 62 and is of ferrous material so as to be attracted upwardly tothe underface of wall 63 thus acting as an armature when theelectromagnet is energized at coil 6!. The aforesaid spring 53 seats atits upper end on the wall 63.

The wall 63 separates the electromagnet from the armature 64 Withoutinterfering with the desired magnetic action therebetween. With myarrangement the cover E may be formed as a single piece without openingstherethrough and therefore the gasoline cannot leak through the cover aswould be the tendency if the armature operated through the cover. I havealso dispensed with any requirement for sealing the electromagnet fromthe armature in the liquid chamber.

When the electromagnet is energized, armature 64 moves upwardly to wall63 thereby allowing ball 49 to seat at 52 when piston 39 starts itsdownward movement. Under such conditions the last part of the throttleclosing movement is retarded by the action of dashpot F. When thesolenoid is de-energized, as in Fig. 2, then spring 53 acts throughplunger 41 to hold ball 49 unseated and against pin 53. Under suchconditions the throttle is allowed to freely close without retardationby dashpot F.

The energization of the electromagnet G may be controlled by anysuitable means according to conditions dealt with. By preference theelectromagnet is controlled in response to speed of the engine or thecar travel, the latter arrangement being illustrated in my drawings. Atsome convenient point in the drive there is provided a governor H whosedrive shaft 65 is driven from a gear 66 carried by the transmissionoutput shaft 26 so that the governor is driven at a speed proportionalto that of the car. The governor, at a predetermined speed, operates tomove sleeve 67 outwardly against the action of the restoring spring 68.If desired, a detent 69 may be provided to control the sleeve which isprovided with a flange l6 engaging one end of a moving switch piece 7!for controlling the governor switch J.

The electrical circuit comprises ground 12 and battery 13 thence throughammeter 14 and ignition switch 15 to coil 6|, switch J and ground 76. Atcar standstill the switch J is closed thereby energizing electromagnet Gso as to render dashpot F operative to retard the last part of throttleclosing. As the car is accelerated from standstill, the governor Hoperates at a predetermined car speed to open switch J therebyde-energizing electromagnet G and rendering dashpot F inoperative toretard throttle closing. While the governor may be arranged to operateat any desired speed, I have obtained good operating functions byarranging the parts so that the governor switch J will open at around 20miles per hour car speed. As the car is-brought to a stop, the governorH operates to accommodate closing of switch J thereby restoring thedashpotF to operation. A spring 11 yieldingly acts on the swingingswitch piece H to close switch J.

Referring to Figs. 5 and 6, I have provided a slightly modifiedarrangement such that when the electromagnet G is energized the dashpotF is rendered inoperative instead of operative as in Fig. 2.

In Fig. 5 the ball 49 is now disposed above the seat 52 and is held onthis seat by the spring 53 when the electromagnet G is de-energizedthereby preventing passage of the fluid from chamber 52 to the outlet 55and rendering the dashpot F operative. When the electromagnet isenergized the plunger 41 is raised as before and ball 49 is free toallow the fluid to flow from chamber 42 through cylinder 54 to outlet 55thereby rendering the dashpot inoperative. In Fig. 6 the governor switchJ is now open at the low car speeds and closes to energize the coil 6|at the relatively higher speeds of the car. The Fig. 5 arrangementoperates otherwise just as described in connection with the Fig. 2system.

The wall 63 is preferably formed relatively thin so that the gap betweenthe electromagnet and armature may be kept to a small dimensionapproximately comparable to an air gap. By such arrangement I avoid thenecessity of an objectionably large electromagnet G or an electromagnetrequiring more than about the amount of current necessary if the wall 63were replaced 1 by an air gap.

The non-ferrous wall 63 acts the same as though it was a very small airgap. Furthermore the wall 53 takes the place of a, customaryintermediary between the armature and iron of the electromagnet commonlyused to prevent magnetic adherence of the armature to the electromagnetwhen the latter is de-energized.

The thin wall section 63, being localized at the armature, will notobjectionably lessen the desired strength of the cover E as a whole asmight well be the case in the event that the whole cover E was formedwith a cross-section equal to that at wall 63.

I claim:

1. In a dashpot device for controlling closing movement of an enginethrottle, a casing structure having a fluid reservoir and a pressurechamber, said casing having an opening at its top, a cover closing saidopening, a dashpot element movably disposed between said reservoir andchamber, a by-pass having a seat, said bypass extending between saidreservoir and chamber, a dashpot-controlling ball in said by-passadapted for movement from a first position accommodating fluid flowthrough the by-pass to a second position engaging said seat therebypreventing passage of fluid through the by-pass, a plunger disposedentirely within said casing structure and below said cover, said plungerbeing adapted for operation to control movement of said ball, anelectromagnet disposed entirely outside of said casing structure andseated on said cover, said electromagnet being adapted to controloperation of said plunger, and an armature connected to said plunger,said armature being disposed below said cover in magnetic associationwith said electromagnet through said cover.

2. In a dashpot device for controlling closing movement of an enginethrottle, a casing structure having a fluid reservoir and a pressurechamber, a dashpot element movably disposed between said reservoir andchamber, a bypass having a seat, said by-pass extending between saidtill reservoir and chamber, a dashpot-controlling ball in said by-passadapted for movement from a first position accommodating fluid flowthrough the by-pass to a second position engaging said seat therebypreventing passage of fluid through the by-pass, a plunger operable froma first position of preventing engagement of said ball with said seat toa second position accommodating movement of said ball to its said secondposition, a spring biasing said plunger to its said first position, andan electromagnet for moving said plunger to its said second position.

3. In a dashpot device for controlling closing movement of an enginethrottle, a casing structure having a fluid reservoir and a pressurechamber, a dashpot element movably disposed between said reservoir andchamber, a by-pass having a seat, said by-pass extending between saidreservoir and chamber, a dashpot-controlling ball in said by-passadapted for movement from a first position accommodating fluid flowthrough the by-pass to a second position engaging said seat therebypreventing passage of fluid through the by-pass, a plunger operable froma first position of holding said ball in its said second position to asecond position accommodating movement of said ball to its said firstposition, a spring biasing said plunger to its said first position, andan electromagnet for moving said plunger to its said second position.

4. In a dashpot device for controlling closing movement of an enginethrottle, a casing structure having a fluid reservoir and a pressurechamber, a dashpot element movably disposed between said reservoir andchamber, a by-pass having a seat, said by-pass extending between saidreservoir and chamber, a dashpot-controlling ball in said by-passadapted for movement from a first position accommodating fluid flowthrough the bypass to a second position engaging said seat therebypreventing passage of fluid through the by-pass, a plunger structurehaving at one end thereof a stem portion engageable with said ball andhaving at the other end thereof an armature portion, a spring biasingsaid plunger so as to cause said stem portion to prevent movement ofsaid ball to its said second position, and an electromagnet cooperablewith said armature portion and adapted when energized to move saidplunger structure so as to accommodate movement of said ball to its saidsecond position.

5. In a dashpot device for controlling closing movement of an enginethrottle, an open top casing structure having a fluid reservoir and apressure chamber, a dashpot element movably disposed between saidreservoir and chamber, a cover closing the top of said casing structure,a by-pass having a seat, said by-pass extending between said reservoirand chamber, a dashpotcontrolling ball in said by-pass adapted formovement from a first position accommodating fluid flow through theby-pass to a second position engaging said seat thereby preventingpassage of fluid through the by-pass, a plunger structure disposedwithin said casing structure and having at the lower end thereof a stemportion engageable with said ball and having at the upper end thereof anenlarged armature portion underlying said cover, a spring acting betweensaid cover and said plunger structure for biasing said plunger structureso as to cause said stem portion to maintain said ball in its saidsecond position, and an electromagnet cooperable with said armatureportion and adapted when energized to move said plunger structure so asto accommodate movement of said ball to its said first position.

6. In a control device of the character described, a liquid reservoir, adashpot operably associated with said reservoir, an electromagnet, anarmature magnetically associated with said electromagnet, and a coverfor said reservoir separating said armature from said electromagnet.

'7. In a control device according to claim 6, said cover comprising abody of non-ferrous material having a magnetic flux transmitting portionengaged by the armature, said cover portion being of materially lesscross-section than other portions of said cover adjacent said armatureengaging portion.

8. In a dashpot device for controlling closing movement of an enginethrottle, a casing structure having a fluid reservoir and a pressurechamber, a dashpot element operably disposed between said reservoir andsaid chamber, a cover for said reservoir, an electromagnet mounted onthe outside of said cover, and means magnetically operable in responseto energization of said electromagnet for controlling operation of saiddashpot element, said magnetically operable means comprising an armaturedisposed within said cover and separated from said electromagnet saidcover.

9. In a dashpot device for controlling closing movement of an enginethrottle, a casing structure having a fluid reservoir and a pressurechamber, a dashpot element operably disposed between said reservoir andsaid chamber, a cover for said reservoir having a portion of itsunderface recessed to provide a cover portion of thin cross-sectionrelative to other portions of said cover adjacent said thin coverportion, an electromagnet mounted on the outside of said cover adjacentsaid thin cover portion, an armature for said electromagnet operablydisposed within said recessed cover portion and separated from saidelectromagnet by said cover, and means operated under control of saidarmature for controlling operation of said dashpot element.

10. In a dashpot device for controlling closing movement of an enginethrottle, a casing structure having a fluid reservoir and a pressurechamber, a dashpot element operably disposed between said reservoir andsaid chamber, a cover for said reservoir having a portion thereof ofthin crosssection relative to other portions of said cover adjacent saidthin cover portion, an electromagnet mounted on the outside of saidcover adjacent said thin cover portion, an armature for saidelectromagnet operably disposed within said cover and separated fromsaid electromagnet by said cover, and means controlled by said armaturefor controlling operation of said dashpot element.

11, In a dashpot device for controlling closing movement of an enginethrottle, a casing structure having a fluid reservoir and a pressurechamber, a dashpot element operably disposed between said reservoir andsaid chamber, a bypass having a seat, said by-pass extending betweensaid reservoir and chamber, a dashpotcontrolling ball in said by-passadapted for movement from a first position accommodating fluid flowthrough the by-pass to a second position engaging said seat therebypreventing passage of fluid through the by-pass, a cover for saidreservoir, an electromagnet mounted on the outside of said cover, and anarmature for said electromagnet adapted to control movement of saidball, said armature being disposed within said cover and separated fromsaid electromagnet by said cover.

12. In a dashpot device for controlling closing movement of an enginethrottle valve, a casing having a portion thereof containing a body offluid, a dashpot element reciprocable in said casing portion and beingso disposed as to divide said casing portion to form a fluid reservoirand a fluid pressure chamber, means providing an operative connectionbetween said throttle valve and dashpot element, spring means biasingsaid throttle valve to its closed position and acting through saidconnection to bias said dashpot element for movement in one of itsdirections of reciprocation, a passage between said reservoir andchamber by-passing said dashpot element, a dashpot-controlling ballvalve for said passage adapted for movement between positions effectingclosing or opening of said passage, means restrictedly venting saidchamber to said reservoir with metering fluid flow therebetween suchthat when said ball valve is positioned to effect closing of saidpassage then said dashpot element will be moved in its said onedirection by said spring means with retarded action thereby retardingclosing movement of said throttle valve, a plunger operable forcontrolling movement of said ball valve, and an electromagnet forcontrolling operation of said plunger.

i3. In a dashpot device according to claim 12, governor controlled meansfor so controlling energization of said electromagnet that said dashpotelement will be moved in its said one direction by said spring meanswith said retarded action only when said spring means acts to bias saidthrottle valve to its closed position under conditions otherwise tendingto stall the engine.

THOMAS M. BALL.

